// ============== Formatting extensions ============================
(function () {
    // Define extensions for a few modes
    CodeMirror.extendMode("css", {
        commentStart: "/*",
        commentEnd: "*/",
        wordWrapChars: [";", "\\{", "\\}"],
        autoFormatLineBreaks: function (text) {
            return text.replace(new RegExp("(;|\\{|\\})([^\r\n])", "g"), "$1\n$2");
        }
    });

    function jsNonBreakableBlocks(text) {
        var nonBreakableRegexes = [/for\s*?\((.*?)\)/,
            /\"(.*?)(\"|$)/,
            /\'(.*?)(\'|$)/,
            /\/\*(.*?)(\*\/|$)/,
            /\/\/.*/];
        var nonBreakableBlocks = [];
        for (var i = 0; i < nonBreakableRegexes.length; i++) {
            var curPos = 0;
            while (curPos < text.length) {
                var m = text.substr(curPos).match(nonBreakableRegexes[i]);
                if (m != null) {
                    nonBreakableBlocks.push({
                        start: curPos + m.index,
                        end: curPos + m.index + m[0].length
                    });
                    curPos += m.index + Math.max(1, m[0].length);
                }
                else { // No more matches
                    break;
                }
            }
        }
        nonBreakableBlocks.sort(function (a, b) {
            return a.start - b.start;
        });

        return nonBreakableBlocks;
    }

    CodeMirror.extendMode("javascript", {
        commentStart: "/*",
        commentEnd: "*/",
        wordWrapChars: [";", "\\{", "\\}"],

        autoFormatLineBreaks: function (text) {
            var curPos = 0;
            var reLinesSplitter = /(;|\{|\})([^\r\n;])/g;
            var nonBreakableBlocks = jsNonBreakableBlocks(text);
            if (nonBreakableBlocks != null) {
                var res = "";
                for (var i = 0; i < nonBreakableBlocks.length; i++) {
                    if (nonBreakableBlocks[i].start > curPos) { // Break lines till the block
                        res += text.substring(curPos, nonBreakableBlocks[i].start).replace(reLinesSplitter, "$1\n$2");
                        curPos = nonBreakableBlocks[i].start;
                    }
                    if (nonBreakableBlocks[i].start <= curPos
                        && nonBreakableBlocks[i].end >= curPos) { // Skip non-breakable block
                        res += text.substring(curPos, nonBreakableBlocks[i].end);
                        curPos = nonBreakableBlocks[i].end;
                    }
                }
                if (curPos < text.length)
                    res += text.substr(curPos).replace(reLinesSplitter, "$1\n$2");
                return res;
            } else {
                return text.replace(reLinesSplitter, "$1\n$2");
            }
        }
    });

    CodeMirror.extendMode("xml", {
        commentStart: "<!--",
        commentEnd: "-->",
        wordWrapChars: [">"],

        autoFormatLineBreaks: function (text) {
            var lines = text.split("\n");
            var reProcessedPortion = new RegExp("(^\\s*?<|^[^<]*?)(.+)(>\\s*?$|[^>]*?$)");
            var reOpenBrackets = new RegExp("<", "g");
            var reCloseBrackets = new RegExp("(>)([^\r\n])", "g");
            for (var i = 0; i < lines.length; i++) {
                var mToProcess = lines[i].match(reProcessedPortion);
                if (mToProcess != null && mToProcess.length > 3) { // The line starts with whitespaces and ends with whitespaces
                    lines[i] = mToProcess[1]
                    + mToProcess[2].replace(reOpenBrackets, "\n$&").replace(reCloseBrackets, "$1\n$2")
                    + mToProcess[3];
                    continue;
                }
            }
            return lines.join("\n");
        }
    });

    function localModeAt(cm, pos) {
        return CodeMirror.innerMode(cm.getMode(), cm.getTokenAt(pos).state).mode;
    }

    function enumerateModesBetween(cm, line, start, end) {
        var outer = cm.getMode(), text = cm.getLine(line);
        if (end == null) end = text.length;
        if (!outer.innerMode) return [{from: start, to: end, mode: outer}];
        var state = cm.getTokenAt({line: line, ch: start}).state;
        var mode = CodeMirror.innerMode(outer, state).mode;
        var found = [], stream = new CodeMirror.StringStream(text);
        stream.pos = stream.start = start;
        for (; ;) {
            outer.token(stream, state);
            var curMode = CodeMirror.innerMode(outer, state).mode;
            if (curMode != mode) {
                var cut = stream.start;
                // Crappy heuristic to deal with the fact that a change in
                // mode can occur both at the end and the start of a token,
                // and we don't know which it was.
                if (mode.name == "xml" && text.charAt(stream.pos - 1) == ">") cut = stream.pos;
                found.push({from: start, to: cut, mode: mode});
                start = cut;
                mode = curMode;
            }
            if (stream.pos >= end) break;
            stream.start = stream.pos;
        }
        if (start < end) found.push({from: start, to: end, mode: mode});
        return found;
    }

    // Comment/uncomment the specified range
    CodeMirror.defineExtension("commentRange", function (isComment, from, to) {
        var curMode = localModeAt(this, from), cm = this;
        this.operation(function () {
            if (isComment) { // Comment range
                cm.replaceRange(curMode.commentEnd, to);
                cm.replaceRange(curMode.commentStart, from);
                if (from.line == to.line && from.ch == to.ch) // An empty comment inserted - put cursor inside
                    cm.setCursor(from.line, from.ch + curMode.commentStart.length);
            } else { // Uncomment range
                var selText = cm.getRange(from, to);
                var startIndex = selText.indexOf(curMode.commentStart);
                var endIndex = selText.lastIndexOf(curMode.commentEnd);
                if (startIndex > -1 && endIndex > -1 && endIndex > startIndex) {
                    // Take string till comment start
                    selText = selText.substr(0, startIndex)
                        // From comment start till comment end
                    + selText.substring(startIndex + curMode.commentStart.length, endIndex)
                        // From comment end till string end
                    + selText.substr(endIndex + curMode.commentEnd.length);
                }
                cm.replaceRange(selText, from, to);
            }
        });
    });

    // Applies automatic mode-aware indentation to the specified range
    CodeMirror.defineExtension("autoIndentRange", function (from, to) {
        var cmInstance = this;
        this.operation(function () {
            for (var i = from.line; i <= to.line; i++) {
                cmInstance.indentLine(i, "smart");
            }
        });
    });

    // Applies automatic formatting to the specified range
    CodeMirror.defineExtension("autoFormatRange", function (from, to) {
        var cm = this;
        cm.operation(function () {
            for (var cur = from.line, end = to.line; cur <= end; ++cur) {
                var f = {line: cur, ch: cur == from.line ? from.ch : 0};
                var t = {line: cur, ch: cur == end ? to.ch : null};
                var modes = enumerateModesBetween(cm, cur, f.ch, t.ch), mangled = "";
                var text = cm.getRange(f, t);
                for (var i = 0; i < modes.length; ++i) {
                    var part = modes.length > 1 ? text.slice(modes[i].from, modes[i].to) : text;
                    if (mangled) mangled += "\n";
                    if (modes[i].mode.autoFormatLineBreaks) {
                        mangled += modes[i].mode.autoFormatLineBreaks(part);
                    } else mangled += text;
                }
                if (mangled != text) {
                    for (var count = 0, pos = mangled.indexOf("\n"); pos != -1; pos = mangled.indexOf("\n", pos + 1), ++count) {
                    }
                    cm.replaceRange(mangled, f, t);
                    cur += count;
                    end += count;
                }
            }
            for (var cur = from.line + 1; cur <= end; ++cur)
                cm.indentLine(cur, "smart");
            cm.setSelection(from, cm.getCursor(false));
        });
    });
})();
